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  • 1. Almotasem, Ahmed
    et al.
    Bergström, Jens
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Physics (from 2013).
    Gåård, Anders
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Physics (from 2013).
    Krakhmalev, Pavel
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Physics (from 2013).
    Holleboom, Thijs Jan
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Physics (from 2013).
    A molecular dynamic study on the influence of carbide particles in ferrite on material transfer during nanoscratching of ferritic iron2016In: Proceedings of the 10th International Tool Conference: TOOL, 10th International TOOL Conference : 04th to 07th October 2016, Bratislava, Slovakia / [ed] Simancik, Frantisek, 2016Conference paper (Refereed)
  • 2.
    AlMotasem, Ahmed Tamer
    et al.
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Physics (from 2013).
    Bergström, Jens
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Physics (from 2013).
    Gåård, Anders
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Physics (from 2013).
    Krakhmalev, Pavel
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Physics (from 2013).
    Holleboom, Thijs
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Physics (from 2013).
    Adhesion between ferrite iron-€“iron/cementite countersurfaces: A molecular dynamics study2016In: Tribology International, ISSN 0301-679X, E-ISSN 1879-2464, Vol. 103, p. 113-120Article in journal (Refereed)
    Abstract [en]

    The adhesive properties of Fe(110)/Fe(110) and Fe3C(001)/Fe(110) countersurfaces have been investigated by using classical molecular dynamics simulations. The simulation results show that Fe3C/Fe exhibits a relatively lower adhesion compared to the Fe/Fe. Additionally, the temperature dependence of the adhesive properties between 300–700 K has been examined. The results demonstrate that, with increasing the temperature, the values of the adhesion force and the work of adhesion continuously decrease in the case of Fe3C/Fe; they initially slightly increase up to 500 K then decrease in the case of Fe/Fe. Furthermore, the effect of lattice coherency between Fe/Fe has been examined and found to slightly reduce the adhesion. These results explain how carbides improve galling resistance of tool steel observed during dry sliding. 

  • 3.
    AlMotasem, Ahmed Tamer
    et al.
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Physics (from 2013). Assiut University, Egypt.
    Bergström, Jens
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Physics (from 2013).
    Gåård, Anders
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Physics (from 2013).
    Krakhmalev, Pavel
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Physics (from 2013).
    Holleboom, Thijs
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Physics (from 2013).
    Tool microstructure impact on the wear behavior of ferrite iron during nanoscratching: An atomic level simulation2017In: Wear, ISSN 0043-1648, E-ISSN 1873-2577, Vol. 370-371, p. 39-45Article in journal (Refereed)
    Abstract [en]

    In the present work, molecular dynamics simulations were used to investigate the impact of the tool microstructure on the wear behavior of ferrite workpiece during nanoscratching. The tool microstructure was modified by varying the carbide (cementite) contents. The simulation results show that dislocations are the primary mechanism for plastic deformation of the workpiece material. It is found that total dislocation length varies significantly depending on the carbide content in the tool. Furthermore, other tribological phenomena were also observed to depend on the carbide contents. For example, the average value of frictional forces decreased while the normal force increases with increasing carbide contents, and hence the friction coefficient was decreased. Additionally, the shape and size of lateral and frontal pileups are lowered. The structural analysis of the pileup region reveals the loss of long range order and start of amorphisation. The temperature distribution of the pileup regions showed an increase of the pileup temperature when carbide is added into tool. The wear volume is considerably reduced when the carbide content increases. The average scratch hardness was found to decrease and the result was analyzed with the theoretical Taylor hardening model.

  • 4.
    AlMotasem, Ahmed Tamer
    et al.
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Physics (from 2013). Department of Physics, Faculty of ScienceAssiut University Assiut Egyp.
    Bergström, Jens
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Physics (from 2013).
    Gåård, Anders
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Physics (from 2013).
    Krakhmalev, Pavel
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Physics (from 2013), Science, Mathematics and Engineering Education Research.
    Holleboom, Thijs Jan
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Physics (from 2013).
    Atomistic insights on the wear/friction behavior of nanocrystalline ferrite during nanoscratching as revealed by molecular dynamics2017In: Tribology letters, ISSN 1023-8883, E-ISSN 1573-2711, Vol. 65, no 3, p. 101-Article in journal (Refereed)
    Abstract [en]

    Using embedded atom method potential, extensive large-scale molecular dynamics (MD) simulations of nanoindentation/nanoscratching of nanocrystalline (nc) iron have been carried out to explore grain size dependence of wear response. MD results show no clear dependence of the frictional and normal forces on the grain size, and the single-crystal (sc) iron has higher frictional and normal force compared to nc-samples. For all samples, the dislocation- mediated mechanism is the primary cause of plastic deformation in both nanoindentation/nanoscratch. However, secondary cooperative mechanisms are varied significantly according to grain size. Pileup formation was observed in the front of and sideways of the tool, and they exhibit strong dependence on grain orientation rather than grain size. Tip size has significant impact on nanoscratch characteristics; both frictional and normal forces monotonically increase as tip radii increase, while the friction coefficient value drops by about 38%. Additionally, the increase in scratch depth leads to an increase in frictional and normal forces as well as friction coefficient. To elucidate the relevance of indentation/scratch results with mechanical properties, uniaxial tensile test was performed for nc-samples, and the result indicates the existence of both the regular and inverse Hall-Petch relations at critical grain size of 110.9 angstrom. The present results suggest that indentation/scratch hardness has no apparent correlation with the mechanical properties of the substrate, whereas the plastic deformation has.

  • 5.
    Bergström, Jens
    et al.
    Karlstad University, Faculty of Technology and Science, Department of Mechanical and Materials Enineering.
    Krakhmalev, Pavel
    Karlstad University, Faculty of Technology and Science, Department of Mechanical and Materials Enineering.
    Gåård, Anders
    Karlstad University, Faculty of Technology and Science, Department of Mechanical and Materials Enineering.
    Lindvall, Fredrik
    Karlstad University, Faculty of Technology and Science, Department of Mechanical and Materials Enineering.
    Galling in sheet metal forming2008In: Proceedings of the IDDRG 2008 Conference: Best in class stamping, 16-18 June 2008, Olofström: Industriellt utvecklingscentrum i Olofström AB , 2008Conference paper (Other academic)
  • 6.
    Dzogbewu, Thywill
    et al.
    Department of Mechanical and Mechatronic Engineering, Bloemfontein, Central University of Technology, Free State, South Africa.
    Yadroitsev, Igov
    Department of Mechanical and Mechatronic Engineering, Bloemfontein, Central University of.
    Krakhmalev, Pavel
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Physics. Karlstad University, Faculty of Technology and Science, Materials Science.
    Yadroitsava, Inna
    Department of Mechanical and Mechatronic Engineering, Bloemfontein, Central University of.
    Du Plessis, Anton
    University of Stellenbosch.
    Optimal process parameters for in-situ alloyed Ti15Mo structures by Direct Metal Laser Sintering2017In: Solid Freeform Fabrication 2017: Proceedings of the 28th Annual InternationalSolid Freeform Fabrication Symposium – An Additive Manufacturing Conference, Austin: University of Texas , 2017, p. 75-96Conference paper (Refereed)
  • 7.
    Gåård, Anders
    et al.
    Karlstad University, Faculty of Technology and Science, Department of Mechanical and Materials Engineering.
    Hallbäck, Nils
    Karlstad University, Faculty of Technology and Science, Department of Mechanical and Materials Engineering.
    Krakhmalev, Pavel
    Karlstad University, Faculty of Technology and Science, Department of Mechanical and Materials Engineering.
    Bergström, Jens
    Karlstad University, Faculty of Technology and Science, Department of Mechanical and Materials Engineering. Karlstad University, Faculty of Technology and Science, Materials Science.
    Temperature effects on adhesive wear in dry sliding contacts2010In: Wear, ISSN 0043-1648, E-ISSN 1873-2577, Vol. 268, no 7-8, p. 968-975Article in journal (Refereed)
  • 8.
    Gåård, Anders
    et al.
    Karlstad University, Faculty of Technology and Science, Materials Science. Karlstad University, Faculty of Technology and Science, Department of Mechanical and Materials Engineering.
    Hirvonen Grytzelius, Joakim
    Karlstad University, Faculty of Technology and Science, Department of Physics and Electrical Engineering.
    Krakhmalev, Pavel
    Karlstad University, Faculty of Technology and Science, Materials Science. Karlstad University, Faculty of Technology and Science, Department of Mechanical and Materials Engineering.
    Zhang, Hanmin
    Karlstad University, Faculty of Technology and Science, Department of Physics and Electrical Engineering.
    Bergström, Jens
    Karlstad University, Faculty of Technology and Science, Department of Mechanical and Materials Engineering. Karlstad University, Faculty of Technology and Science, Materials Science.
    Experimental study of the relationship between temperature and adhesive forces for low-alloyed steel, stainless steel and titanium using atomic force microscopy in ultra-high vacuum2008In: Journal of Applied Physics, ISSN 0021-8979, E-ISSN 1089-7550, ISSN 0021-8979, Vol. 103, no 12, article id 124301Article in journal (Refereed)
  • 9.
    Gåård, Anders
    et al.
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Physics (from 2013).
    Karlsson, Patrik
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Physics (from 2013).
    Krakhmalev, Pavel
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Physics (from 2013).
    Broitman, Esteban
    Linköpings universitet, Tunnfilmsfysik.
    Nano-scale friction of multi-phase powder metallurgy tool steels2015In: Advanced Materials Research, ISSN 1022-6680, E-ISSN 1662-8985, Vol. 1119, p. 70-74Article in journal (Refereed)
    Abstract [en]

    Friction is a fundamental phenomenon in tribology involving complex mechanisms between thecontacting surfaces. Measurements of friction are often made using devices with substantially largercontact area than dimensions corresponding to microstructural features of the materials. Hence, for multi-phase materials,influence of particular microstructural constituents is not resolved. In the present work, a tribometerwith a contact area in the nano-scale range was used to map friction for different types of tool steelswith different chemical- and phase composition. Owing to the small tip radius, frictionalcharacteristics of primary carbides and the steel matrix were measured and compared. Dependingon chemical composition, a difference was observed where the coefficient of friction wasapproximately twice higher for the steel possessing highest coefficient of friction, including bothcarbides and the steel matrix.

  • 10.
    Gåård, Anders
    et al.
    Karlstad University, Faculty of Technology and Science, Materials Science. Karlstad University, Faculty of Technology and Science, Department of Mechanical and Materials Engineering.
    Krakhmalev, Pavel
    Karlstad University, Faculty of Technology and Science, Materials Science. Karlstad University, Faculty of Technology and Science, Department of Mechanical and Materials Engineering.
    Bergström, Jens
    Karlstad University, Faculty of Technology and Science, Department of Mechanical and Materials Engineering. Karlstad University, Faculty of Technology and Science, Materials Science.
    Influence of tool steel microstructure on origin of galling initiation and wear mechanisms under dry sliding against carbon steel sheets2009In: Wear, ISSN 0043-1648, E-ISSN 1873-2577, Vol. 267, no 1-4, p. 387-393Article in journal (Refereed)
  • 11.
    Gåård, Anders
    et al.
    Karlstad University, Faculty of Technology and Science, Materials Science. Karlstad University, Faculty of Technology and Science, Department of Mechanical and Materials Engineering.
    Krakhmalev, Pavel
    Karlstad University, Faculty of Technology and Science, Materials Science. Karlstad University, Faculty of Technology and Science, Department of Mechanical and Materials Engineering.
    Bergström, Jens
    Karlstad University, Faculty of Technology and Science, Department of Mechanical and Materials Engineering. Karlstad University, Faculty of Technology and Science, Materials Science.
    Microstructural characterization and wear behavior of (Fe,Ni)-TiC MMC prepared by DMLS2006In: Journal of Alloys and Compounds, ISSN 0925-8388, E-ISSN 1873-4669, Vol. 421, no 1-2, p. 166-171Article in journal (Refereed)
  • 12.
    Gåård, Anders
    et al.
    Karlstad University, Faculty of Technology and Science, Materials Science. Karlstad University, Faculty of Technology and Science, Department of Mechanical and Materials Engineering.
    Krakhmalev, Pavel
    Karlstad University, Faculty of Technology and Science, Materials Science. Karlstad University, Faculty of Technology and Science, Department of Mechanical and Materials Engineering.
    Bergström, Jens
    Karlstad University, Faculty of Technology and Science, Department of Mechanical and Materials Engineering. Karlstad University, Faculty of Technology and Science, Materials Science.
    Wear mechanisms in deep drawing of carbon steel: correlation to laboratory testing2008In: Tribotest, ISSN 1354-4063, Vol. 14, no 1, p. 1-9Article in journal (Refereed)
  • 13.
    Gåård, Anders
    et al.
    Karlstad University, Faculty of Technology and Science, Department of Mechanical and Materials Engineering.
    Krakhmalev, Pavel
    Karlstad University, Faculty of Technology and Science, Materials Science. Karlstad University, Faculty of Technology and Science, Department of Mechanical and Materials Engineering.
    Bergström, Jens
    Karlstad University, Faculty of Technology and Science, Department of Mechanical and Materials Engineering. Karlstad University, Faculty of Technology and Science, Materials Science.
    Wear mechanisms in galling: cold work tool materials sliding against high-strength carbon steel sheets2009In: Tribology letters, ISSN 1023-8883, E-ISSN 1573-2711, Vol. 33, no 1, p. 45-53Article in journal (Other academic)
    Abstract [en]

    Transfer and accumulation of adhered sheet material, generally referred to as galling, is the major cause for tool failure in sheet metal forming. In this study, the galling resistances of several tool steels were evaluated against dual-phase high-strength carbon steel using a SOFS tribometer, in which disc-shaped tools were slid against a real sheet surface in dry sliding test conditions. Three different frictional regimes were identified and characterized during sliding, and any transition in friction corresponded to a transition in wear mechanisms of the sheets. The performance of the tools depended on load, material and the particular frictional regime. Best overall performance was obtained by nitrogen-alloyed powder metallurgy tool steel.

  • 14.
    Gåård, Anders
    et al.
    Karlstad University, Faculty of Technology and Science, Materials Science. Karlstad University, Faculty of Technology and Science, Department of Mechanical and Materials Engineering.
    Krakhmalev, Pavel
    Karlstad University, Faculty of Technology and Science, Materials Science. Karlstad University, Faculty of Technology and Science, Department of Mechanical and Materials Engineering.
    Bergström, Jens
    Karlstad University, Faculty of Technology and Science, Department of Mechanical and Materials Engineering. Karlstad University, Faculty of Technology and Science, Materials Science.
    Hallbäck, Nils
    Karlstad University, Faculty of Technology and Science.
    Galling resistance and wear mechanisms - cold work tool materials sliding against carbon steel sheets2007In: Tribology letters, ISSN 1023-8883, E-ISSN 1573-2711, Vol. 26, no 1, p. 67-72Article in journal (Refereed)
  • 15.
    Hanson, Magnus
    et al.
    Department of Materials Science, Uppsala University.
    Gåård, Anders
    Karlstad University, Faculty of Technology and Science, Materials Science. Karlstad University, Faculty of Technology and Science, Department of Mechanical and Materials Engineering.
    Hogmark, Sture
    Department of Materials Science, Uppsala University.
    Krakhmalev, Pavel
    Karlstad University, Faculty of Technology and Science, Materials Science. Karlstad University, Faculty of Technology and Science, Department of Mechanical and Materials Engineering.
    Bergström, Jens
    Karlstad University, Faculty of Technology and Science, Department of Mechanical and Materials Engineering. Karlstad University, Faculty of Technology and Science, Materials Science.
    Comparison of two test methods for evaluation of forming tool materials2008In: Tribotest, ISSN 1354-4063, Vol. 14, no 2, p. 147-158Article in journal (Refereed)
  • 16.
    Jackman, Henrik
    et al.
    Karlstad University, Faculty of Technology and Science, Department of Physics and Electrical Engineering.
    Krakhmalev, Pavel
    Karlstad University, Faculty of Technology and Science, Department of Mechanical and Materials Engineering.
    Svensson, Krister
    Karlstad University, Faculty of Technology and Science, Department of Physics and Electrical Engineering.
    Bending modulus of freestanding carbon nanotubes2010Conference paper (Other academic)
  • 17.
    Jackman, Henrik
    et al.
    Karlstad University, Faculty of Technology and Science, Department of Physics and Electrical Engineering.
    Krakhmalev, Pavel
    Karlstad University, Faculty of Technology and Science, Department of Mechanical and Materials Enineering.
    Svensson, Krister
    Karlstad University, Faculty of Technology and Science, Department of Physics and Electrical Engineering.
    Direct Measurements Of Bending Stiffness And Rippling Phenomena In Free-Standing Carbon Nanotubes2011Conference paper (Refereed)
  • 18.
    Jackman, Henrik
    et al.
    Karlstad University, Faculty of Technology and Science, Department of Physics and Electrical Engineering.
    Krakhmalev, Pavel
    Karlstad University, Faculty of Technology and Science, Department of Mechanical and Materials Engineering.
    Svensson, Krister
    Karlstad University, Faculty of Technology and Science, Department of Physics and Electrical Engineering.
    High resolution SEM imaging of carbon nanotubes: deconvolution and retrieval of intrinsic nanotube dimensions2012Conference paper (Refereed)
    Abstract [en]

    Characterizing physical properties of individual nanotubes is crucial for their implementation in nano electromechanical systems (NEMS). This requires measurements on suspended or free-standing structures together with accurate determination of the nanotubes dimensions. In situ methods are often used where physical measurements are performed inside electron microscopes [1-3]. Transmission electron microscopy (TEM) has the advantage of high resolution, providing accurate determination of both dimensions and the internal structure. The space inside a TEM is however rather restricted, leaving limited room for additional probes [4]. Scanning electron microscopy (SEM) on the other hand, has a large specimen chamber which facilitates the addition of probes, but the image resolution is lower, making the evaluation of material properties less accurate or even impossible for very thin nanotubes [1]. One way to solve this is to first measure the physical properties inside an SEM, and then determine the diameter using a TEM afterwards [1]. This approach requires transfer of the nanotube from the SEM to a suitable TEM sample holder, and analysis of the same sample-location in both instruments. It would thereby be advantageous to obtain accurate structural information directly inside the SEM [2]. We have studied the mechanisms involved in SEM image formation of small multiwalled nanotubes, 2-5 nm in diameter. The electron-probe shape in an SEM broadens the sample details, and the image can be seen as a convolution of the secondary electron yield at each sample position and the probe shape. By comparing SEM and TEM images, we found that the probe intensity profile was best described by a linear combination of Gaussian and Lorentzian distributions. Using the obtained probe shape, the SEM images could then be deconvoluted to reveal more details, including the inner diameter in some cases. We also show how the outer diameter can be obtained by differentiating image profiles, a method that does not require any detailed knowledge regarding the probe shape and is reliable down to dimensions comparable to the electron-probe size. This significantly improves the capabilities of in-situ SEM experiments by enabling accurate characterizations of nanofibres inside SEM instruments, without the need for subsequent TEM imaging

  • 19.
    Jackman, Henrik
    et al.
    Karlstad University, Faculty of Technology and Science, Department of Physics and Electrical Engineering.
    Krakhmalev, Pavel
    Karlstad University, Faculty of Technology and Science, Department of Mechanical and Materials Engineering.
    Svensson, Krister
    Karlstad University, Faculty of Technology and Science, Department of Physics and Electrical Engineering.
    Image formation mechanisms in scanning electron microscopy of carbon nanotubes,and retrieval of their intrinsic dimensions.2013In: Ultramicroscopy, ISSN 0304-3991, Vol. 124, p. 35-39Article in journal (Refereed)
    Abstract [en]

    We present a detailed analysis of the image formation mechanisms that are involved in the imaging of carbon nanotubes with scanning electron microscopy (SEM). We show how SEM images can be modelled by accounting for surface enhancement effects together with the absorption coefficient for secondary electrons, and the electron-probe shape. Images can then be deconvoluted, enabling retrieval of the intrinsic nanotube dimensions. Accurate estimates of their dimensions can thereby be obtained even for structures that are comparable to the electron-probe size (on the order of 2 nm). We also present a simple and robust model for obtaining the outer diameter of nanotubes without any detailed knowledge about the electron-probe shape.

  • 20.
    Jackman, Henrik
    et al.
    Karlstad University, Faculty of Technology and Science, Department of Physics and Electrical Engineering.
    Krakhmalev, Pavel
    Karlstad University, Faculty of Technology and Science, Department of Mechanical and Materials Engineering.
    Svensson, Krister
    Karlstad University, Faculty of Technology and Science, Department of Physics and Electrical Engineering.
    Large variations in the onset of rippling in concentric nanotubes.2014In: Applied Physics Letters, ISSN 0003-6951, E-ISSN 1077-3118, Vol. 104, article id 021910Article in journal (Refereed)
    Abstract [en]

    We present a detailed experimental study of the onset of rippling in highly crystalline carbon nanotubes. Modeling has shown that there should be a material constant, called the critical length, describing the dependence of the critical strain on the nanotube outer radius. Surprisingly, we have found very large variations, by a factor of three, in the critical length. We attribute this to a supporting effect from the inner walls in multiwalled concentric nanotubes. We provide an analytical expression for the maximum deflection prior to rippling, which is an important design consideration in nanoelectromechanical systems utilizing nanotubes.

  • 21.
    Jackman, Henrik
    et al.
    Karlstad University, Faculty of Technology and Science, Department of Physics and Electrical Engineering.
    Krakhmalev, Pavel
    Karlstad University, Faculty of Technology and Science.
    Svensson, Krister
    Karlstad University, Faculty of Technology and Science, Department of Physics and Electrical Engineering.
    Measurements of the critical strain for rippling in carbon nanotubes2011In: Applied Physics Letters, ISSN 0003-6951, Vol. 98, no 18, p. 3 pages-Article in journal (Refereed)
    Abstract [en]

    We report measurements of the bending stiffness in free standing carbon nanotubes, using atomic force microscopy inside a scanning electron microscope. Two regimes with different bending stiffness were observed, indicative of a rippling deformation at high curvatures. The observed critical strains for rippling were in the order of a few percent and comparable to previous modeling predictions. We have also found indications that the presence of defects can give a higher critical strain value and a concomitant reduction in Youngs modulus.

  • 22.
    Jackman, Henrik
    et al.
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Physics.
    Krakhmalev, Pavel
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Physics.
    Svensson, Krister
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Physics.
    Mechanical behavior of carbon nanotubes in the rippled and buckled phase2015In: Journal of Applied Physics, ISSN 0021-8979, E-ISSN 1089-7550, Vol. 117, no 8, p. 084318-Article in journal (Refereed)
    Abstract [en]

    We have studied the mechanical behavior of multi-walled carbon nanotubes for bending strains beyond the onset for rippling and buckling. We found a characteristic drop in the bending stiffness at the rippling and buckling onset and the relative retained stiffness was dependent on the nanotube dimensions and crystallinity. Thin tubes are more prone to buckle, where some lose all of their bending stiffness, while thicker tubes are more prone to ripple and on average retain about 20\% of their bending stiffness. In defect rich tubes the bending stiffness is very low prior to rippling but these tubes retain up to 70\% of their initial bending stiffness.

  • 23.
    Karlsson, Patrik
    et al.
    Karlstad University, Faculty of Technology and Science, Department of Mechanical and Materials Engineering.
    Eriksson, Jenny
    Dalarna University.
    Gåård, Anders
    Karlstad University, Faculty of Technology and Science, Department of Mechanical and Materials Engineering.
    Krakhmalev, Pavel
    Karlstad University, Faculty of Technology and Science, Department of Mechanical and Materials Engineering.
    Olsson, Mikael
    Dalarna University.
    Bergström, Jens
    Karlstad University, Faculty of Technology and Science, Department of Mechanical and Materials Engineering.
    Galling resistance evaluation of tool steels by two different laboratory test methods for sheet metal forming2012In: Lubrication Science, ISSN 0954-0075, E-ISSN 1557-6833, Vol. 24, no 6, p. 263-272Article in journal (Refereed)
    Abstract [en]

    Adhesive accumulation of work material on the tool surface is today a major problem in many sheet metal-forming applications. Different laboratory test methods are used to investigate galling with respect to different tool materials, lubricants and process conditions. In the present study, the galling resistance of a modern nitrogen-alloyed powder metallurgy tool steel and an conventional ingot cast D2 type tool steel was evaluated under lubricated sliding against ferritic stainless steel sheets using a commercial pin-on-disc (POD) and an in-house made slider-on-flat-surface (SOFS) tribotester. The investigated tool steels ranked similarly in terms of galling resistanc in both test methods. However, sliding distances to galling were longer for the SOFS equipment due to continuous sliding on new lubricated sheet surface. Best performance was demonstrated by the powder metallurgy tool steel treated to 65 HRC. Differences in friction behaviour and galling initiation were analysed on the basis of the two different working conditions, i.e. open (SOFS) and closed (POD) tribosystems. Copyright © 2012 John Wiley & Sons, Ltd.

  • 24.
    Karlsson, Patrik
    et al.
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Physics.
    Gåård, Anders
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Physics.
    Krakhmalev, Pavel
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Physics.
    Influence of tool steel microstructure on friction and initial material transfer2014In: Wear, ISSN 0043-1648, E-ISSN 1873-2577, Vol. 319, no 1-2, p. 12-18Article in journal (Refereed)
    Abstract [en]

    An investigation was conducted to study the influence of tool steel microstructure on initial material transfer and friction. Two different powder metallurgy tool steels and an ingot cast tool material were tested in dry sliding against 1.4301, 1.4162, Domex 355 MC and Domex 700 MC sheet materials. It was found that tool steel hard phase heights influence initial material transfer and friction. The coefficient of friction increased with decreasing tool steel hard phase heights at 50 N normal load and initial material transfer occurred around protruding hard phases. At higher load of 500 N the sheet material adhered to both the tool steel matrix and hard phases. Coefficient of friction decreased with increasing proof strength of the sheet material at 500 N normal load.

  • 25.
    Karlsson, Patrik
    et al.
    Karlstad University, Faculty of Technology and Science, Department of Mechanical and Materials Engineering.
    Gåård, Anders
    Karlstad University, Faculty of Technology and Science, Department of Mechanical and Materials Engineering.
    Krakhmalev, Pavel
    Karlstad University, Faculty of Technology and Science, Department of Mechanical and Materials Engineering.
    Bergström, Jens
    Karlstad University, Faculty of Technology and Science, Department of Mechanical and Materials Engineering.
    Galling Resistance and Wear Mechanisms for Cold Work Tool Steels in Lubricated Sliding Against High Strength Stainless Steel Sheets2010In: Tribology of manufacturing processes: Proceedings of the 4th International Conference on Tribology in Manufacturing Processes (ICTMP 2010), Volume 2, Paris: Presses de l'Ecole des mines , 2010, p. 603-612Conference paper (Refereed)
  • 26.
    Karlsson, Patrik
    et al.
    Karlstad University, Faculty of Technology and Science, Department of Mechanical and Materials Engineering.
    Gåård, Anders
    Karlstad University, Faculty of Technology and Science, Department of Mechanical and Materials Engineering.
    Krakhmalev, Pavel
    Karlstad University, Faculty of Technology and Science, Department of Mechanical and Materials Engineering.
    Bergström, Jens
    Karlstad University, Faculty of Technology and Science, Department of Mechanical and Materials Engineering.
    Galling resistance and wear mechanisms for cold-work tool steels in lubricated sliding against high strength stainless steel sheets2012In: Wear, ISSN 0043-1648, E-ISSN 1873-2577, Vol. 286-287, p. 92-97Article in journal (Refereed)
    Abstract [en]

    Tool damage in sheet metal forming of stainless steel is of high concern for the forming industry. In the present work, ingot cast AISI D2 and advanced powder metallurgy tool steel (PM) cold-work tool steels were evaluated and ranked regarding wear mechanisms and galling resistance. Wear tests were performed using a slider-on-flat-surface (SOFS) tribometer in sliding against austenitic–ferritic (duplex) stainless steel sheets at different contact pressures in lubricated conditions. The best galling resistance was observed for the nitrogen alloyed PM tool steels. Abrasive scratching of the tool surfaces and transfer of sheet material due to adhesive wear were the main metal forming tool surface damage mechanisms. By increasing the hardness of one PM sheet metal forming tool grade, the galling resistance was enhanced.

  • 27.
    Karlsson, Patrik
    et al.
    Karlstad University, Faculty of Technology and Science, Department of Mechanical and Materials Engineering.
    Gåård, Anders
    Karlstad University, Faculty of Technology and Science, Department of Mechanical and Materials Engineering.
    Krakhmalev, Pavel
    Karlstad University, Faculty of Technology and Science, Department of Mechanical and Materials Engineering.
    Bergström, Jens
    Karlstad University, Faculty of Technology and Science, Department of Mechanical and Materials Engineering.
    Influence of size and distribution of hard phases in tool steels on the early stage of galling2012In: / [ed] Harald Leitner, Regina Kranz, Angelica Tremmel, 2012, p. 469-476Conference paper (Refereed)
    Abstract [en]

    In sheet metal forming processes, contact pressures are relatively high and total sliding distances are long, which demands tool steels to prevent tool damage and to resist galling. Galling is related to microscopic and macroscopic material transfer, but, the mechanisms of initiation are not thoroughly understood.

     

    To investigate galling initiation, lubricated sliding testing in the Slider-On-Flat-Surface (SOFS) tribometer was performed for ingot cast (IC) AISI D2 type and nitrogen alloyed powder metallurgy (PM) tool steel. The sheet grade was EN 1.4509 ferritic stainless steel. To reveal mechanisms in the early stages of galling initiation, transfer and accumulation of sheet material to the tool surfaces were characterized using AFM and SEM.

     

    It was found that already after a short sliding distance, transfer of sheet material occurred covering both the matrix and the hard phases. Macroscopic analysis of the contact area showed that initial material transfer and further lump growth occurred at positions corresponding to high plastic strains in the sheet material. Even though initial material transfer was observed for both tested tool steels, the sliding distance to the point where transfer and further lump formation occurred was longer for the PM tool steel. This was discussed in correlation to differences in size and distribution of the hard phases in the tool steels, which was confirmed by AFM and SEM.

  • 28.
    Karlsson, Patrik
    et al.
    Karlstad University, Faculty of Technology and Science, Department of Mechanical and Materials Engineering.
    Gåård, Anders
    Karlstad University, Faculty of Technology and Science, Department of Mechanical and Materials Engineering.
    Krakhmalev, Pavel
    Karlstad University, Faculty of Technology and Science, Department of Mechanical and Materials Engineering.
    Berhe-Larsson, Johanna
    Karlstad University, Faculty of Technology and Science, Department of Mechanical and Materials Engineering.
    Influence of tool steel hard phase orientation and shape on galling2014In: Advanced Materials Research, ISSN 1022-6680, E-ISSN 1662-8985, Vol. 966-96, p. 249-258Article in journal (Refereed)
    Abstract [en]

    Conventionally manufactured cold work tool steel is often used in sheet metal forming as die material. Due to the forging process, the as-cast network structure of carbides is broken into elongated particles. Depending on the tool cross-section, the orientation and shape of carbides in the active tool surface is different. In the present research, the influence of tool steel hard phase orientation and shape on galling was investigated. D2 type tool steel was cut in three different orientations and tested in lubricated sliding conditions against AISI 304 austenitic stainless steel. Tests were performed using a Slider-On-Flat-Surface and galling was detected by changes in friction and post-test microscopy. The lubricant was Castrol FST8 using 5 g/m2 sheet material. Results showed a strong correlation between sliding distance to galling and tool steel hard phase orientation and shape at low loads, whereas high load contact resulted in early galling in all cases. Material transfer was observed mainly to the tool steel matrix. The worst performance was observed for specimens cut so that the tool steel hard phase, M7C3 carbides in the D2 steel, were oriented along the sliding direction, which resulted in longer open tool matrix areas contacting the sheet material.

  • 29.
    Karlsson, Patrik
    et al.
    Karlstad University, Faculty of Technology and Science, Department of Mechanical and Materials Engineering.
    Krakhmalev, Pavel
    Karlstad University, Faculty of Technology and Science, Department of Mechanical and Materials Engineering.
    Gåård, Anders
    Karlstad University, Faculty of Technology and Science, Department of Mechanical and Materials Engineering.
    Bergström, Jens
    Karlstad University, Faculty of Technology and Science, Department of Mechanical and Materials Engineering.
    Influence of work material proof stress and tool steel microstructure on galling initiation and critical contact pressure2013In: Tribology International, ISSN 0301-679X, E-ISSN 1879-2464, Vol. 60, p. 104-110Article in journal (Refereed)
    Abstract [en]

    EN 1.4301 (austenitic), EN 1.4509 (ferritic), EN 1.4162 (duplex) and EN 1.4310 C1000 (metastable austenitic) stainless steels were tested in lubricated sliding against an ingot cast EN X153WCrMoV12 and powder metallurgy nitrogen alloyed Uddeholm Vancron 40 tool steels to reveal critical to galling contact pressure, Pcr. The calculated Pcr were higher for steels with higher strength. At P>Pcr, due to plastic flow of sheet material, the tool is damaged substantially and wear-induced matrix damage causes rapid galling initiation. At P<Pcr, galling was not observed. The powder metallurgy tool steel was more resistant to galling against all tested stainless steels. Better performance was associated with fine and homogeneously distributed hard phases preventing intensive wear of the tool steel matrix.

  • 30.
    Kazantseva, N.
    et al.
    Institute of Metal Physics, Russia; Ural Federal University, Russia.
    Krakhmalev, Pavel
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Physics (from 2013).
    Thuvander, M.
    Chalmers University of Technology, Sweden.
    Yadroitsev, I.
    Central University of Technology, South Africa.
    Vinogradova, N.
    Institute of Metal Physics, Russia.
    Ezhov, I.
    Institute of Metal Physics, Russia.
    Martensitic transformations in Ti-6Al-4V (ELI) alloy manufactured by 3D Printing2018In: Materials Characterization, ISSN 1044-5803, E-ISSN 1873-4189, Vol. 146, p. 101-112Article in journal (Refereed)
    Abstract [en]

    In the present investigation, Ti-6Al-4V ELI samples were manufactured by the powder-bed fusion (PBF) process using the laser sintering (LS) technology. Microstructure, chemical and phase constitution, and mechanical properties were studied by means of the transmission electron microscopy, atom probe tomography, X-ray diffraction, nanoindentation and mechanical testing. It was found that the structure of LS samples consisted of two different variants of metastable phases, namely the hexagonal alpha' martensitic phase and small amounts of the orthorhombic alpha '' martensitic phase. The martensitic alpha'-phase was formed because of the high cooling rates of the LS method, The {10 (1) over bar2} <(1) over bar 011 > hexagonal martensite tensile twins were observed in the microstructure of the as-build alloy. Small areas with inner twinning martensitic plates, which are typical for the metastable orthor-hombic martensitic phase in titanium alloys, were identified by the transmission electron microscopy. Atom probe tomography (APT) confirmed localization of beta-stabilizing elements at interfaces, presumably at the twin or lamella boundaries. The structure and origin of the martensitic phases in 3D printed Ti-6Al-4V alloys are discussed with respect to in-situ heat treatment during manufacturing.

  • 31.
    Kazantseva, Natalia
    et al.
    Institute of Metal Physics, Ural Branch of the Russian Academy of Science, Ekaterinburg.
    Krakhmalev, Pavel
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Physics (from 2013).
    Fredriksson, Gunnel
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Physics (from 2013).
    Yadroitsev, Igov
    Twins in SLM Ti alloy2017In: Titan, ISSN 2075-2903, no 2, p. 8-15Article in journal (Refereed)
  • 32.
    Kazantseva, Natalia
    et al.
    Institute of Metal Physics, Ural Branch of the Russian Academy of Science, Ekaterinburg.
    Krakhmalev, Pavel
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Physics (from 2013).
    Yadroitsev, Igov
    Department of Mechanical and Mechatronic Engineering, Bloemfontein, Central University of Technology, Free State, South Africa.
    Fefelov, A.
    Reg Engn Ctr Laser & Addit Technol, Ekaterinburg, Russia.
    Merkushev, A
    Reg Engn Ctr Laser & Addit Technol, Ekaterinburg, Russia.
    Ilyinikh, M
    Reg Engn Ctr Laser & Addit Technol, Ekaterinburg, Russia.
    Vinogradova, N
    Inst Met Phys, Ekaterinburg, Russia.
    Ezhov, I
    Inst Met Phys, Ekaterinburg, Russia.
    Kurennykh, T
    Inst Met Phys, Ekaterinburg, Russia.
    Oxygen and nitrogen concentrations in the Ti-6Al-4V Alloy manufactured by direct metal laser sintering (dmls) process2017In: Materials letters (General ed.), ISSN 0167-577X, E-ISSN 1873-4979, Vol. 209, p. 311-314Article in journal (Refereed)
    Abstract [en]

    Two machines from two scientific centers (Russia and South Africa) were used for the manufacturing of the Ti6Al4V alloys by the direct metal laser sintering. The chemical composition of powders complies with the ASTM F-136 (grade 5), ASTM B348 (grade 23) standard for medical applications. Analysis of the oxygen and nitrogen contamination in DMLS alloys was done with Van de Graaff accelerator with two Mega Volts. It is found that structures of the samples manufactured with two different machines used the same regimes are close to each other. TEM studies found the metastable martensitic structure and silicon nitride Si3N4. It was found that the oxygen and nitrogen contents in both samples are within the normal range for medical grade titanium alloys.

  • 33.
    Kazantseva, N.V.
    et al.
    Institute of Metal Physics, Ekaterinburg, Russia.
    Krakhmalev, Pavel
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Physics (from 2013).
    Fredriksson, Gunnel
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Physics (from 2013).
    Vinogradova, N.I.
    Institute of Metal Physics, Ekaterinburg, Russia.
    Yadroitsev, Igor
    Central University of Technology, Bloemfontein 9300, South Africa.
    Twins in SLM Ti-4Al-6V Alloys2016Conference paper (Refereed)
  • 34.
    Kinnear, Allan
    et al.
    Department of Mechanical and Mechatronic Engineering, Bloemfontein, Central University of Technology, Free State, South Africa.
    Krakhmalev, Pavel
    Karlstad University, Faculty of Technology and Science, Materials Science. Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Physics (from 2013), Science, Mathematics and Engineering Education Research.
    Yadroitsava, Inna
    Department of Mechanical and Mechatronic Engineering, Bloemfontein, Central University of Technology, Free State, South Africa.
    Yadroitsev, Igov
    Department of Mechanical and Mechatronic Engineering, Bloemfontein, Central University of Technology, Free State, South Africa.
    Manufacturing, microstructure and mechanical properties of selective laser melted Ti6Al4V-Cu2017Conference paper (Refereed)
  • 35.
    Krakhmalev, Pavel
    Karlstad University, Faculty of Technology and Science, Materials Science. Karlstad University, Faculty of Technology and Science, Department of Mechanical and Materials Engineering.
    Effect of microstructure on edge wear mechanisms in WC-Co, WOM 20072007Conference paper (Refereed)
  • 36.
    Krakhmalev, Pavel
    Karlstad University, Faculty of Technology and Science, Department of Mechanical and Materials Engineering.
    Energy input effect on the microstructure, morphology and stability of single track in selective laser melting2012Conference paper (Refereed)
  • 37.
    Krakhmalev, Pavel
    Karlstad University, Faculty of Technology and Science, Materials Science. Karlstad University, Faculty of Technology and Science, Department of Mechanical and Materials Engineering.
    Isothermal grain growth in mechanically alloyed nanostructured Fe80Ti8B12 alloy2003In: Materials Letters, ISSN ISSN: 0167-577X, Vol. 57, no 22/23, p. 3671-3675Article in journal (Refereed)
    Abstract [en]

    Isothermalgraingrowth in a mechanicallyalloyednanostructured Fe80Ti8B12alloy was investigated at 915–985 K by TEM and XRD methods. Crystallization of the amorphous phase and grain coarsening stages were observed, and each stage was analyzed using models of a graingrowth with dragging of grain boundaries and of normal graingrowth, respectively. Activation energies were calculated to be 300±10 and 280±10 kJ/mol using the models.

  • 38.
    Krakhmalev, Pavel
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Physics, Science, Mathematics and Engineering Education Research.
    Microstructure and phase constitution of Ti-SiC coatings fabricated by selective laser melting2013Conference paper (Refereed)
  • 39.
    Krakhmalev, Pavel
    Karlstad University, Faculty of Technology and Science, Materials Science. Karlstad University, Faculty of Technology and Science, Department of Mechanical and Materials Engineering.
    On the abrasion of ultrafine WC-Co by fine abrasive particles2007In: Transactions of Nonferrous Metals Society of China, ISSN 1003-6326, E-ISSN 2210-3384, Vol. 17, no 6, p. 1287-1293Article in journal (Refereed)
  • 40.
    Krakhmalev, Pavel
    Karlstad University, Faculty of Technology and Science, Materials Science. Karlstad University, Faculty of Technology and Science, Department of Mechanical and Materials Engineering.
    On the abrasion of ultrafine WC-Co hardmetals by small SiC abrasive2008In: Tribology letters, ISSN 1023-8883, E-ISSN 1573-2711, Vol. 30, no 1, p. 35-39Article in journal (Refereed)
  • 41.
    Krakhmalev, Pavel
    Karlstad University, Faculty of Technology and Science, Materials Science. Karlstad University, Faculty of Technology and Science, Department of Mechanical and Materials Engineering.
    Preparation of Mo(Si,Al)2-ZrO2 nanocomposite powders by mechanical alloying, International Journal of Refractory Metals and Hard Materials, Volume 22, Issues 4-5, July-September 2004, Pages 205-2092004Article in journal (Refereed)
  • 42.
    Krakhmalev, Pavel
    Karlstad University, Faculty of Technology and Science, Materials Science. Karlstad University, Faculty of Technology and Science, Department of Mechanical and Materials Engineering.
    Tool materials and applications, research experience at KaU, Swedish-Egyptian workshop2007In: Swedish-Egyptian Workshop 2007 (representation of Karlstad University), Cairo, Egypt, SMRDI, 14-16 May 2007Article in journal (Other academic)
  • 43.
    Krakhmalev, Pavel
    et al.
    Karlstad University, Faculty of Technology and Science, Materials Science. Karlstad University, Faculty of Technology and Science, Department of Mechanical and Materials Engineering.
    Bergström, Jens
    Karlstad University, Faculty of Technology and Science, Department of Mechanical and Materials Engineering. Karlstad University, Faculty of Technology and Science, Materials Science.
    Hot wear of Mo(Si,Al)2-base composites sliding against an aluminum alloy, NORDTRIB 20042004In: NORDTRIB 2004, Proceeding of the 11-th Nordic Symposium on Tribology: Tromsø, Harstad, Hurtigruten, [Bodø], Norway, June [1 - 5], 2004, Tromsö, 2004, p. 307-317Conference paper (Refereed)
  • 44.
    Krakhmalev, Pavel
    et al.
    Karlstad University, Faculty of Technology and Science, Materials Science. Karlstad University, Faculty of Technology and Science, Department of Mechanical and Materials Engineering.
    Bergström, Jens
    Karlstad University, Faculty of Technology and Science, Department of Mechanical and Materials Engineering. Karlstad University, Faculty of Technology and Science, Materials Science.
    Tribological behavior and wear mechanisms of MoSi2-base composites sliding against AA6063 alloy at elevated temperature2006In: Wear, ISSN 0043-1648, E-ISSN 1873-2577, Vol. 260, no 4-5, p. 450-457Article in journal (Refereed)
  • 45.
    Krakhmalev, Pavel
    et al.
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Physics (from 2013).
    Fredriksson, Gunnel
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Physics (from 2013).
    Svensson, Krister
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Physics (from 2013).
    Yadroitsev, Igor
    Bloemfontein Cent Univ Technol South Africa.
    Yadroitsava, Ina
    Bloemfontein Cent Univ Technol South Africa.
    Thuvander, M.
    Chalmers University.
    Peng, R.
    Linköping University.
    Microstructure, solidification texture, and thermal stability of 316 L stainless steel manufactured by laser powder bed fusion2018In: Metals, ISSN 2075-4701, Vol. 8, no 8, p. 1-18, article id 643Article in journal (Refereed)
    Abstract [en]

    This article overviews the scientific results of the microstructural features observed in 316 L stainless steel manufactured by the laser powder bed fusion (LPBF) method obtained by the authors, and discusses the results with respect to the recently published literature. Microscopic features of the LPBF microstructure, i.e., epitaxial nucleation, cellular structure, microsegregation, porosity, competitive colony growth, and solidification texture, were experimentally studied by scanning and transmission electron microscopy, diffraction methods, and atom probe tomography. The influence of laser power and laser scanning speed on the microstructure was discussed in the perspective of governing the microstructure by controlling the process parameters. It was shown that the three-dimensional (3D) zig-zag solidification texture observed in the LPBF 316 L was related to the laser scanning strategy. The thermal stability of the microstructure was investigated under isothermal annealing conditions. It was shown that the cells formed at solidification started to disappear at about 800 °C, and that this process leads to a substantial decrease in hardness. Colony boundaries, nevertheless, were quite stable, and no significant grain growth was observed after heat treatment at 1050 °C. The observed experimental results are discussed with respect to the fundamental knowledge of the solidification processes, and compared with the existing literature data.

  • 46.
    Krakhmalev, Pavel
    et al.
    Karlstad University, Faculty of Technology and Science, Department of Mechanical and Materials Engineering.
    Fredriksson, Gunnel
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Physics (from 2013).
    Yadroitsava, I.
    Cent Univ Technol, Dept Mech & Mechatron Engn, Private Bag X20539, ZA-9300 Bloemfontein, South Africa.
    Kazantseva, N.
    Urals Branch Acad Sci, Inst Met Phys, Ekaterinburg 620219, Russia.
    Plessis, A. du
    Univ Stellenbosch, CT Scanner Facil, Private Bag 11, ZA-7602 Stellenbosch, South Africa.
    Yadroitsev, I.
    Cent Univ Technol, Dept Mech & Mechatron Engn, Private Bag X20539, ZA-9300 Bloemfontein, South Africa.
    Deformation Behavior and Microstructure of Ti6Al4V Manufactured by SLM2016In: Physics Procedia, ISSN 1875-3892, E-ISSN 1875-3892, Vol. 83, p. 778-788Article in journal (Refereed)
  • 47.
    Krakhmalev, Pavel
    et al.
    Karlstad University, Faculty of Technology and Science, Materials Science. Karlstad University, Faculty of Technology and Science, Department of Mechanical and Materials Engineering.
    Fredriksson, Gunnel
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Physics.
    Yadroitsava, Inna
    Yadroitsev, Igor
    In situ heat treatment in selective laser melted martensitic AISI420 stainless steels2015In: Materials & Design, ISSN 0264-1275, Vol. 87, p. 380-385Article in journal (Refereed)
  • 48.
    Krakhmalev, Pavel
    et al.
    Karlstad University, Faculty of Technology and Science, Materials Science. Karlstad University, Faculty of Technology and Science, Department of Mechanical and Materials Enineering.
    Gåård, Anders
    Karlstad University, Faculty of Technology and Science, Materials Science. Karlstad University, Faculty of Technology and Science, Department of Mechanical and Materials Enineering.
    Bergström, Jens
    Karlstad University, Faculty of Technology and Science, Materials Science. Karlstad University, Faculty of Technology and Science, Department of Mechanical and Materials Enineering.
    Influence of tool steel microstructure on origin of galling initiation and wear mechanisms under dry sliding against a carbon steel sheet, WOM 20072009Conference paper (Refereed)
  • 49.
    Krakhmalev, Pavel
    et al.
    Karlstad University, Faculty of Technology and Science, Materials Science. Karlstad University, Faculty of Technology and Science, Department of Mechanical and Materials Engineering.
    Rodil, Adeva
    Bergström, Jens
    Karlstad University, Faculty of Technology and Science, Department of Mechanical and Materials Engineering. Karlstad University, Faculty of Technology and Science, Materials Science.
    Influence of microstructure on the abrasive edge wear of WC–Co hardmetals2007In: Wear, ISSN 0043-1648, E-ISSN 1873-2577, Vol. 263, no 1-6, p. 240-245Article in journal (Refereed)
  • 50.
    Krakhmalev, Pavel
    et al.
    Karlstad University, Faculty of Technology and Science, Materials Science. Karlstad University, Faculty of Technology and Science, Department of Mechanical and Materials Engineering.
    Ström, E.
    Li, C.
    Microstructure and properties stability of Al-alloyed MoSi2 matrix composites2004In: Intermetallics (Barking), ISSN 0966-9795, E-ISSN 1879-0216, Vol. 12, no 2, p. 225-233Article in journal (Refereed)
12 1 - 50 of 81
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